While assembled electronic circuitry has been dramatically reduced in size the use of soldering as a method for forming both an electrical and fixable attachment of electronic components to a substrate has remained quite prevalent. However, such attachments generally require that the electronic components be held in desired positions prior to completing the aforementioned fixable attachments.
A number of solutions for holding components in such desired positions have been developed and used with some success. For example, it is known to use a tack agent to temporarily secure such components in desired positions while solder bond or solder ball connections are made through the application of heat. However, generally such tack agent remains as a contaminant that requires the assembly to be subjected to an extra processing step designed to remove such contamination. For some of the aforementioned solutions, a fluxing agent is provided separately from the tack agent, for example by applying such fluxing agent in a distinct application step, separate from the application of the tack agent. In other solutions the fluxing agent is provided in a combination with the tack agent, for example where a solder paste is used as the tack agent and fluxing agent is either added thereto or pre-reacted therewith.
In still other solutions, a tack agent and a di-carboxylic acid fluxing agent are admixed where upon soldering, the tack agent either volatilizes or decomposes (see, U.S. Pat. No. 5,177,134). However, as a di-carboxylic acid fluxing agent is taught, it is likely that even small amounts of contamination from such di-carboxylic acid fluxing agent can remain and cause reliability issues if a separate cleaning step is not employed. In US Published Application No. 2009/0294515, embodiments where either specialized process equipment is required for fluxless solder bonding or a carboxylic acid fluxing agent are employed. Therefore new solutions that eliminate the need for such specialized equipment by providing tacking properties and a non-carboxylic acid fluxing agent to achieve desirable solder reflow are needed.